422 JS. D. Dana—Depression of Southern - England 
has almost no slope at high tide, the tide reached that point. 
Yet a spring flood often produces a rise of 17 feet at Shelton, 
and causes an average pitch in the river’s surface for the ten 
miles to the Sound of nearly 1$ feet per mile ; and there is oc- 
casionally a flood causing a rise of 22 feet, and connea eet an 
average pitch of more than 2 feet a mile. 
o ascertain the oe pitch below Birmingham or Derby 
for the Glacial flood we have important data in the height of 
the upper terrace between these places and the Sound. 
The Shelton and Birmingham level of 95 feet ee below 
Derby to the “ Derby Narrows.” Below the Narrows—about 1} 
miles from Shelton and 1 mile from Derby—the valley on its 
east side expands rather abruptly about the mouth of T'wo-mile 
Creek ; it then contracts again on that side, through the rising 
of “Turke Hill,” but regains . i ey below through 
the retreat of the hills on the west s 
ow the terrace below the Nar aoe just north of Two-mile 
Creek, has a height of 75 feet above high-water mark; and a 
mile below this, on the west side, of 70 feet. Hence, in pass- 
ing the Derby Narr OWS, a distance of three-fourths of a mile, 
the level appears to have fallen 20 feet, which would indicate 
a tremendous rush of waters between the rocky hills 
The following table contains the heights of the terraces rd 
measured along the valiey to the Sound, the above included: 
Feet. 
At Shelton, opposite Derby -- Dap ao Oa 
, m. below, Derby, east side, below the Narrows. ---- -------- be 
2m. WOSt SG). 2.002) eo eee <aan 
4m. . Onset dG. . ccd, yes sid 
5 m . ONSE MING i ce ec eee ee 46 
6 m be WOME GGG... enc dpe ee conn ee 48 
6°8 m. - west side, near a stream..----.------- -- i 
7°5 m. i? 4m. above Railroad crossing. - oven eee ee ee 
825m. near Stratford b 4: Se ET Tay ae 
9°75 m. a 4m, from the Sound ...._-.-..-.--- 1232 
The average decline in the height of the terrace from pane 
, where, being 95 feet above flood-level, it is 100 above “ e- 
igiak to the Sound i is over 10 feet a mile.+ The rate of decline 
should not be uniform because it would “ with the oh 
i 
* The 5: Retiite given in this memoir, where attributed to others, 
obtained by the writer, and all of them with al hand eve, excepting four, above 
120 feet, hich were measured 
wih = § tributary; 
_+ Five miles below Derby, west of the pervarng mh one mile up its tribute 
Fermill River, I found the height of the terrace 60 feet. This height was, 
hue vooked the tributary, and not properly that of the Hon satonic. 
* 
